From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6478773169 for ; Tue, 20 Feb 2024 15:07:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708441633; cv=none; b=GOgE78rqxPX5xw+lpFFRUONhhFS+enhgAc/JcnezXFxdtqKxjXHwIDUCfP3DIHBSMcEuihvjdnQEHRbrWf1zElaggJdpo3wl8NzVtODKziX+9UR3Mnc4671RY/GZIFuFIx5Ql3a6Mta5USMtg/iQh1AtQF4FshPXsRz5Hm9Zcu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708441633; c=relaxed/simple; bh=1YOAXq4n3TKhseMTUr23nV7sFBO6wOP38L/DOsPMQvY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=imGPoo5HTpjKygc4Gc5gk5Y0jIpZBwB7sJLu7boPDRapv8HpDPRULgsxQm9Z9Bb7auBxA7f87BiOq1hSRmvwF1EtXp3oqxqbjPZjcQhVfdiR8B6br+BueOC1isWsmARk4OAJ1PG5Fi+4ixiOo3V1neeRglt3CZ8URgLHd0oZFXk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D190C433C7; Tue, 20 Feb 2024 15:07:11 +0000 (UTC) Date: Tue, 20 Feb 2024 10:08:57 -0500 From: Steven Rostedt To: Mathieu Desnoyers Cc: Oleg Nesterov , wenyang.linux@foxmail.com, Masami Hiramatsu , Ingo Molnar , Mel Gorman , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: Re: [PATCH] coredump debugging: add a tracepoint to report the coredumping Message-ID: <20240220100857.3f450059@gandalf.local.home> In-Reply-To: <776b842b-b19f-44bf-bc34-ac756fce7466@efficios.com> References: <20240217104924.GB10393@redhat.com> <20240219112926.77ac16f8@gandalf.local.home> <20240219170038.GA710@redhat.com> <20240219122825.31579a1e@gandalf.local.home> <776b842b-b19f-44bf-bc34-ac756fce7466@efficios.com> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 19 Feb 2024 13:01:16 -0500 Mathieu Desnoyers wrote: > No ? Those hook on sched_process_free, which is the actual point where the > task is freed (AFAIR after it's been a zombie and then waited for by another > task). Bah, you're correct. It *used to* be attached to sched_process_exit, and the function callback still has that name. It was commit afcab63665742 ("tracing: Use trace_sched_process_free() instead of exit() for pid tracing") that changed it. > > AFAIU, "sched_process_exit" is issued close to the point where the task exits > (it should not go back to userspace after that). "sched_process_free" is done > when the task is really being removed. > > Between "sched_process_exit" and "sched_process_free", the task can still be > observed by a trace analysis looking at sched and signal events: it's a zombie at > that stage. Right, thanks for reminding me what I did ;-) I guess I'm starting to get to "that age". -- Steve